Malignant tumor is a primary cause of death for Japanese, and in the face of statistics, one out of three people dies due to malignant tumor. The long time efforts dramatically have improved the results of operative therapy, radiation therapy, chemotherapy, and molecular targeted drugs against malignant tumors. However, the death rate caused by malignant tumor is still high, and there is a need for the development of novel therapeutical modality effective for malignant tumors.
Oncolytic virus therapy as a new therapy method is getting attention because of its direct cytocidal effect. For example, several clinical trials utilizing oncolytic adenoviruses and herpes simplex viruses that are DNA viruses have been carried out for treatment of brain tumor and breast cancer, with the published results demonstrating their safeness and anticancer efficacy.
On the other hand, enteroviruses of Picornaviridae that are RNA viruses have no genome integration in host cells after infection, have little risk of malignant transformation due to the gene mutation, and have no oncogene, thus possessing a relatively higher safety to human beings. Still further, enteroviruses have a fast growth rate in cells, and thus are expected to show a quick and high oncolytic effect.
For example, Patent Literature 1 discloses oncolytic virotherapy utilizing enteroviruses such as coxsackievirus (CV) A21 (CVA21) type, echovirus (EV) 6 (EV6) type, EV7 type, EV11 type, EV12 type, EV13 type, and EV29 type. In addition, Patent Literature 2 discloses oncolytic virotherapy utilizing enteroviruses such as CVA13 type, CVA15 type, CVA18 type, CVA21 type, EV1 type, EV7 type, EV8 type, and EV22 type.